Gas tank drain lock



INVENTOR. sscuazuf srnys May 10, 1949. A. M. MALLUK GAS TANK DRAIN LOCK Filed May 2, 1946 ci' Zz Patented May 10, 1949 ENCE 1 Claim.

l This invention relates to locks for liquid tanks. There are a great many locks adapted to close the entrance drain neck, or lling neck of fuel tanks so that the uel Will. not b'e syphoned oi or otherwise disturbed. However, almost every tank and particularly automobile gasoline tanks are provided with a drainage plug for cleaning purposes, and it is desirable that such plug be provided since tanks should be drained and cleaned periodically to prevent sediment, sludge and other foreign matter from contaminating the fuel.

An object of this invention is to provide a, lock which will protect the drainage plug from tampering. rXhe ordinary drainage plug may be removed With a wrench and the tank may be emptied regardless of whether or not the neck or iilling spout is in itself protected.

An object of this invention is to provide a locking mechanism Which Will prevent tampering with the drainage plug.

A further object is to provide a lock which Will be protected from the Weather and the elements but which, nevertheless, may readily be operated by a person having a key.

A further object of my invention is to provide a device which can be readily adapted to all present day vehicles. The present day gas tank plugs come in three sizes, and previous locks Would not lit all three sizes. An object of this invention is to provide in combination With the lock plugs having a standard base adapted to fit the lock but with diierent sized Shanks to t different tanks.

In the accompanying drawings- Fig. 1 is a sectional side elevation of my improved plug lock.

Fig. 2 is a perspective view of the lock in open position.

Fig. 3 is a perspective view of the protective casing and Washer.

Figures 4, 5 and 6 are side elevations of three plugs adapted to t tanks now in use.

Fig. '7 is a cross-sectional elevation of a modified form of my invention adapted to use any of the plugs shown in Figs. 4, 5 and 6.

Every tank, such as tank lil, is provided with a plug drain consisting oi a housing II adapted to receive the plug I2. These plugs may vary in diameter, as shown by the plugs I3 and I4, but there are only three plugs, namely, plugs having the same diameter as I2, I3 and I4, in common use. One of the advantages of my mechanism over the prior art rests in the fact that I provide plugs having diierent diameters but with standlid ard bases, as will be more fully described hereafter. My lock il consists of a base plate I8, a side member I9 and an additional side member 2li hinged to the member I9 at 2I. A spring latch-hook 22 is pressed outwardly by a spring 23 connected by means of a rod 24 to the lock 25, which is seated in the recess 26, in the annular face of the side member I9. A catch member 2'! is adapted to engage the spring latch 22 to hold the lock in a closed position. The member 20 has a lower Wall 28 and an upper Wall 29, both of which extend inwardly, the lower Wall 28 contacting the base I8 While the upper Wall forms with the corresponding wall 30 of the member I 9 an annular opening adapted to engage the plug. In order to protect the lock in the closed position, I provide a cover 3l, which may be made of rubber, natural or plastic, and which is internally threaded at 32 to engage the threads 33 on the annular sides of the lock I1. An opening 34 is provided in the base of the cover 3l so that the cover may be removed. The bottom of the base plate is provided With a iin or key 35 in order that it may be held against rotation when the cover is applied or removed. If desired, the n or key 35 may be omitted and a kerf or slot used in its place. A Washer or gasket 36 may be provided to protect the top of the lock if desired. The Washer or gasket as shown in Fig. 3 has an opening 31 to allow the passage of the plug. Shown in Figs. 4, 5 and 6 plugs I2, I3 and I4 have different diameter shanks 46, 4I and 42 terminating in a standard sized head 43. Each plug is threaded only to the point and is recessed at 46. It has an annular ange 41, which is identical in each case, and a second recess 48. 'Ihe annular opening formed When the lock is closed is slightly larger than the iiange 4l but smaller than the upper surface of the head 43. In installing my device the plug I2, I3 or I4, depending upon the internal size of the housing II, is substituted for the conventional plug. The washer 36, if used, is then placed over the head of the plug and the lock I1 snapped into place. The cover 3I is then screwed on to the lock and the operation is complete.

It will be understood that because of the fact that the annular opening formed in the lock is larger than the flange 4l the Whole lock may be rotated without unscrewing or tightening the plug. The iin, or key, 35 may be held While the cover is put on to prevent the lock from rotating and similarly it may be held when the cover is removed to prevent rotation. It will be understood that my lock will be used in connection 3 with a tank lock similar to that shown in my Patent No. 2,375,671.

In the form shown in Fig. 7 a similar plug 50 is inserted in the tank l through the tubular member 53. The tubular member 53 is provided With an inwardly extending annular collar 54 adapted to surround the shank 55 of the plug 50 and rest on the head 56 of the plug 50, and the head 56 of the plug 50 is provided with a kerf 51 so that it may be screwed into position through the tubular member 53. The tubulary memberl 53 is provided With an annular groove 58. There is also provided a lock plug 60 with a locking earT 6l adapted to engage the annular groove 58 soas` to prevent anyone unscrewing the plug 50. A gasket 59 may be provided and a covering' 62 of rubber or other protective materia1 having arlin- Wardly extending top edge 63 engaging the recess 64 in the tubular member 53. It. will be understood that a key will be provided to move the` ear 6l in and out of engagement with the groove 58. It will also be appreciated that there-y Will be enough clearance betweenthe shankof.

the:v stud and the inwardly extending walls of the; tubular member so that rotation of the tubu1ar member will not unscrew the plug I claim:

In combination with a tank drainage plug having a universal head and an annular flange of smaller diameter adjacent said head, of a lock to cover said plug, said lock comprising a base, a pair of hinged members, one of said members engaging said base and each of said members having semi-annular recesses adapted to cover Said head and loosely surrounding said annular flange whereby said lockv may be freely rotated Without turning said plug, a cover for said lock and means for holding said lock stationary While the cover is removed or placed on said lock.

ASSAD M. MALLUK.

REFERENCES CITED The fQllowi-n-g: references are of record in the le oi this patent:

UNITED STATES PATENTS Number Name Date 13221354:l` Mitchell Apr. 3, 1917V 1,503,213' Smith Oct. 1.2,` 192,6 2,131,060. Mfalluk Sept. 27, 1938 2294,922 I\Eal1ukY Sept. 8, 1942 2,345,949 Robbins: Apr; 4,4 19.44 

